Universal contact of strongly interacting fermions at finite temperatures

作者:Hu Hui; Liu Xia Ji; Drummond Peter D*
来源:New Journal of Physics, 2011, 13: 035007.
DOI:10.1088/1367-2630/13/3/035007

摘要

The recently discovered universal thermodynamic behavior of dilute, strongly interacting Fermi gases also implies a universal structure in the many-body pair-correlation function at short distances, as quantified by the contact I. Here, we theoretically calculate the temperature dependence of this universal contact for a Fermi gas in free space and in a harmonic trap. At high temperatures above the Fermi degeneracy temperature, T greater than or similar to TF, we obtain a reliable non-perturbative quantum virial expansion up to third order. At low temperatures, we compare different approximate strong-coupling theories. These make different predictions, which need to be tested either by future experiments or by advanced quantum Monte Carlo simulations. We conjecture that in the universal unitarity limit, the contact or correlation decreases monotonically with increasing temperature, unless the temperature is signif

  • 出版日期2011-3-16